*{
	margin: 0px;
	padding: 0px;
}
	h1, h2, h3, h4, h5, h6, strong{
			font-weight:800;
			font-size:20px;
			vertical-align:middle;
			color: black;
		}
	#all{
		width: 100%;
		height: 800px;
		position: relative;
	}
	#all img{
		width: 100%;
		position: absolute;
	}
	#a{
		width: 500px auto;
		margin: 400px 450px;
		height: 700px;
		position: absolute;
	}
	.denglu{
		width: 500px;
		padding: 30px ;
		line-height: 40px;
		margin: 0px  100px;
		position: absolute;
	}
	.denglu input{
		width: 130px;
		height: 20px;
	}
	.button{
		width: 200px auto;
		margin: 0px 100px;
		height: 30px;
	}
	.button input{
		width: 0px auto;
		height: 20px;
	}
	.denglu span{
		display: none;
		color: red;
	}
	.back{
		margin: 30px 0px 0px 0px;
		float: left;
	}